1. Field of the Invention
This invention relates to a differential signal transmission cable and a differential signal transmission aggregated cable, which are designed for as high frequency signal transmission as a few GHz or higher in a differential manner.
2. Description of the Related Art
For high frequency signal transmission at a few GHz or higher, differential signal transmission has been adopted. In the differential signal transmission, two phase-inverted (180 degrees out of phase) signals are transmitted in twin electrically insulated wires respectively, and at a receiving end of the twin electrically insulated wires, a difference between the two signals is synthesized and output. In the differential signal transmission, directions of flow of currents through the twin electrically insulated wires are opposite each other. The differential signal transmission therefore allows for decreasing outward electromagnetic radiation. Also, because noise is superimposed equally on the twin electrically insulated wires, the differential signal transmission allows for cancelling out effects of the noise at the receiving end of the twin electrically insulated wires.
As a transmission path for as high frequency signal transmission at a few GHz or higher, a conventional differential signal transmission cable 300 as shown in FIG. 3 is known that comprises a Twinax cable 303 including twin electrically insulated wires 301, which are arranged side by side in contact with each other, and a drain wire 302, which is arranged in contact with and parallel to both of the twin electrically insulated wires 301, and a shield tape 304, which is wound around a circumference of that Twinax cable 303 including the drain wire 302.
Refer to e.g., JP-A-2011-091959.